JPH07309050A - Printer - Google Patents

Abstract

PURPOSE:To provide a simple structure not requiring a large number of assembling processes, capable of stably transmitting driving force and achieving the enhancement of the durability of a gear, the prevention of noise and the enhancement of printing quality especially in a serial printer. CONSTITUTION:The driving force transmission mechanism of a printer is constituted of a ribbon driving gear 22 for transmitting ribbon taking-up driving force and a drive shaft 4 having the speed reducing gear 3 of a bevel gear for transmitting the driving force of a printing means provided thereon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus, and more particularly to a power transmission structure for a serial printer having bevel gears.

[0002]

2. Description of the Related Art A conventional printer of this type adjusts the backlash of a bevel gear by using a washer or the like.

[0003]

In the printer constructed as described above, adjustment man-hours are required, and the backlash cannot be adjusted completely, so that the bevel gear easily escapes. As a result, the amount of energy loss increases, causing wear and noise, and the driving force transmitted by the bevel gears is used for the printing means, so that the printing quality varies.

Therefore, the present invention solves such a problem, and its object is to improve the durability of gears by a simple structure which requires less assembly steps and can transmit stable driving force. It is an object to provide a structure capable of preventing noise and improving print quality.

[0005]

In order to solve the above problems, in the printer of the present invention, a carriage equipped with a printing means reciprocates in a direction perpendicular to the recording paper conveyance direction, and the recording paper is passed through a ribbon. In a printer that prints on, a power transmission shaft member that is driven to rotate by a drive source and a power transmission shaft member that is arranged at one end of the power transmission shaft member such that movement of the power transmission shaft member is restricted in the axial direction A worm gear that transmits power to a winding mechanism that winds the ribbon, a first bevel gear that is disposed at the other end of the power transmission shaft and that transmits power to a printing mechanism that drives the carriage, and a first bevel gear. When the power transmission shaft member is moved to the worm gear side by the worm gear, the second bevel gear is the first bevel gear and is meshed with the second bevel gear. When Located between the Omugia, when being moved to the first bevel gear side Conversely, the second bevel gear, characterized in that it is located in the worm gear in the opposite direction of the first bevel gear.

Further, the second bevel gear is characterized in that it is provided with a substantially cylindrical locking portion with which the end face on the small diameter side of the first bevel gear abuts.

[0007]

According to the printer constructed as described above, since the first bevel gear is always on the side to be moved by the second bevel gear, the first bevel gear is in the meshing direction with the second bevel gear. Is always biased.

Further, since the substantially cylindrical engaging portion with which the end surface on the small diameter side of the first bevel gear abuts is arranged, the first bevel gear may approach the second bevel gear more than necessary. Since it is not possible, it is possible to prevent problems due to excessive meshing.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a printer using one embodiment of the present invention. This printer is roughly divided into the main body drive (Fig.
A part), around the carriage (B part in FIG. 1), around the paper feed mechanism (C part in FIG. 1), around the paper guide (D part in FIG. 1: lower part around the paper feed), around ribbon cassette (FIG. 1) E part). Each structure will be described below.

FIG. 2 is a perspective view around the main body drive of a printer using one embodiment of the present invention, 1 is a motor as a power source, 2 is a motor gear fixed to the motor shaft of the motor 1, and 3 is a motor gear.
Is a reduction gear that has a spur gear that meshes with the motor gear 2 and is rotatably supported by the drive shaft 4. Reference numeral 5 is a ribbon reduction gear that has a worm gear at one end and a spur gear at the other end and is fixed to the drive shaft 4. Reference numeral 6 is a gear, 6 is a paper feed drive gear that meshes with the spur gear of the ribbon reduction gear 5, 22 is a ribbon winding shaft that serves to feed the ink ribbon 81-1 by the rotation of the ribbon reduction gear 5,
Reference numeral 7 denotes a paper feed belt which meshes with the paper feed drive gear 6 and transmits the power of the paper feed drive gear 6.

Reference numeral 8 is a paper feed belt pulley A that serves to regulate the path of the paper feed belt 7, 9 is a paper feed belt pulley B that serves to regulate the path of the paper feed belt 7, and 10 is a bevel gear of the reduction gear 3. A carriage reduction gear having an engaging bevel gear and a spur gear, 11 is a carriage reduction gear 1
A carriage transmission gear that meshes with a spur gear of 0, a carriage drive pulley 12 that has a spur gear that meshes with the carriage transmission gear 11 and pulley teeth that mesh with the carriage drive belt 14, and a pulley tooth 13 that meshes with the carriage drive belt 14. It is a carriage driven pulley having a.

Reference numeral 15 is a carriage drive shaft fixed to a carriage drive belt, 16 is a slide plate fixed to the motor shaft of the motor 1 and generating a timing signal necessary for printing, and 17 is a function of detecting the position of the carriage 31. Is a platen fixed to the main body frame 20, and 19 is a driven pulley plate to which a driven pulley shaft for supporting the carriage driven pulley 13 is fixed.

FIG. 3 is a front view showing the structure of the ribbon reduction gear 4 and the carriage reduction gear 10 and the reduction gear 3 of the bevel gear, and FIG. 4 is a sectional view. The drive shaft 4 that rotatably supports the reduction gear 3 is press-fitted into the ribbon reduction gear 5, and receives the rotating shaft by the main body frame 20 and the bearing 21. Since the bearing 21 is sandwiched between the body frame 20 and the motor 1, it is securely fixed.

The power of the motor 1 is transmitted to the reduction gear 3 through the motor gear 2 to rotate the drive shaft 4. The force for rotating the ribbon drive gear 22 in the direction of arrow f becomes a force for moving the ribbon reduction gear 5 in the direction of arrow g, and pulls the drive shaft 4 in the direction of arrow g. The reduction gear 3 is fixed to the drive shaft 4 by an E ring, and receives a force in the direction of arrow g simultaneously with the drive shaft 4 to close the gap with the carriage reduction gear 10, and the step 10-1 of the carriage reduction gear 10 is a reduction gear. Since it serves as a stopper for the upper surface 3-1 of 3, the backlash of both bevel gears is adjusted and stable driving force transmission is possible at a fixed position.

FIG. 5 is a perspective view showing a structure around a carriage of a printer using one embodiment of the present invention, and 31 has a groove portion 31-1 (not shown) for engaging with the carriage drive shaft 15. Carriage, 32 is a print head fixed to the carriage 31, 33 is a head FFC for sending driving power to the print head 32, 34 is a front carriage guide shaft fixed to the main body frame 20, and 35 is fixed to the main body frame 20. Carriage 3 is behind the carriage guide shaft
1 can be translated in the directions of the arrow i1 and the arrow i2.

FIG. 6 is a perspective view showing a structure around a paper feeding mechanism of a printer using one embodiment of the present invention, 41 is a paper feeding frame fixed to the main body frame 20, and 42 is a paper feeding frame.
Is a paper feed pulley driven by the paper feed belt 7, 4
3 is a paper feed gear fixed to the paper feed shaft 44 and meshing with the gear of the paper feed pulley 42; 49 (not shown) is a paper feed roller pivotally supported on the paper feed shaft 44; A paper pressing roller rotatably supported by a pressing shaft 46 and urging the recording paper 50 against a paper feeding roller, 47 is a paper feeding cover for covering the paper feeding frame 41, and 48 is a function for reducing the path load of the recording paper 50. Is a guide roller.

FIG. 7 is a perspective view showing a structure around a paper guide of a printer using one embodiment of the present invention. Reference numeral 61 is a paper guide having a tunnel-shaped hole for guiding the recording paper 50. .

FIG. 8 is a perspective view showing a structure around a ribbon cassette of a printer using one embodiment of the present invention.
Is a ribbon frame attached to the body frame 20,
81 is a ribbon cassette. The above is the overall configuration of the printer using one embodiment of the present invention.

The operation will be described below. When the motor 1 is energized, the motor gear 2 rotates in the direction of arrow a, and the reduction gear 3 rotates in the direction of arrow b in response to the rotation, so that the drive shaft 4
Rotates in the direction of arrow b. The rotation of the reduction gear 3 is transmitted from the carriage reduction gear 10 to the carriage transmission gear 11 to rotate the carriage drive pulley 12 in the direction of arrow d.
When the carriage drive pulley 12 is rotated in the direction of arrow d,
The carriage drive belt 14 rotates in the direction of arrow d. The carriage drive shaft 15 fixed to the carriage drive belt 14 reciprocates in the arrow e1 and arrow e2 directions.

Since the carriage drive shaft 15 gives a moving force to the groove 31-1, the carriage 31 carrying the print head 32 reciprocates in the directions of arrows i1 and i2. Desired printing can be performed by detecting the position of the carriage 31 by the reset detector 17 and energizing the print head 32 with a timing signal generated through the slit plate 16. On the other hand, a ribbon winding shaft 22 that receives a driving force from the ribbon reduction gear 5 and rotates in the direction of arrow p
Serves to rotate the ribbon feed roller 81-2 in the direction of arrow q and feed the ink ribbon 81-1 in the direction of arrow r. Further, the recording paper 50 is fed around the paper feeding mechanism (C portion) at a predetermined timing.

The printer using one embodiment of the present invention described above was a two-sheet printer used especially for incorporating an ECR (electronic cash register), but the power transmission structure of the present invention is Any printer having a shaft member having a worm gear and a bevel gear on the same axis can be used.

[0022]

As described above, according to the present invention, in a printer that prints on a recording sheet via a ribbon, a carriage equipped with a printing unit reciprocates in a direction orthogonal to the conveyance direction of the recording sheet and is driven. A power transmission shaft member that is rotationally driven from a power source, and a winding that winds a ribbon by integrally rotating with the power transmission shaft member and arranged at one end of the power transmission shaft member so that movement of the power transmission shaft member is restricted in the axial direction. A worm gear that transmits power to the take-up mechanism, a first bevel gear that is disposed at the other end of the power transmission shaft and that transmits power to the printing mechanism that drives the carriage, and a first bevel gear that meshes with the first bevel gear. When the power transmission shaft member is moved to the worm gear side by the worm gear, the second bevel gear is positioned between the first bevel gear and the worm gear. Then When the pair is moved to the first bevel gear side, the second bevel gear is positioned in the opposite direction to the worm gear of the first bevel gear, so that the first bevel gear is always the second bevel gear. The first bevel gear is always biased in the meshing direction with the second bevel gear.

Further, since the second bevel gear is provided with the substantially cylindrical locking portion with which the end face on the small diameter side of the first bevel gear abuts, the first bevel gear is provided with the first bevel gear more than necessary. Since the second bevel gear cannot be approached, there is no excessive meshing.

Therefore, since the backlash of the bevel gear can be adjusted without increasing the number of parts, wear of the gear can be prevented. Noise can be prevented. Printing quality is improved. The number of assembly steps can be reduced. The advantage is obtained.

As described above, according to the present invention, it is possible to provide a printer having high durability and high print quality without changing the basic structure, and the practical effect of the present invention is extremely great. Is.

[Brief description of drawings]

FIG. 1 is a perspective view of a printer using an embodiment of the present invention.

FIG. 2 is a perspective view around a main body drive of a printer using one embodiment of the present invention.

FIG. 3 is an explanatory view of a mechanism of a ribbon reduction gear, a carriage reduction gear, and a reduction gear of the present invention.

FIG. 4 is an explanatory diagram of a mechanism of a ribbon reduction gear, a carriage reduction gear, and a reduction gear of the present invention.

FIG. 5 is a perspective view showing a structure around a carriage of a printer using an embodiment of the present invention.

FIG. 6 is a perspective view showing a structure around a paper feeding mechanism of a printer using one embodiment of the present invention.

FIG. 7 is a perspective view showing a structure around a paper guide of a printer using an embodiment of the present invention.

FIG. 8 is a perspective view showing a structure around a ribbon cassette of a printer using one embodiment of the present invention.

[Explanation of symbols]

 1 Motor 2 Motor Gear 3 Reduction Gear 4 Drive Shaft 5 Ribbon Reduction Gear 20 Body Frame 21 Bearing 22 Ribbon Drive Gear 31 Carriage 32 Print Head 43 Paper Feed Gear 81 Ribbon Cassette

Claims (2)

[Claims] 1. A printer for printing on a recording sheet via a ribbon, wherein a carriage equipped with a printing unit reciprocates in a direction perpendicular to the recording sheet conveying direction, and a power transmission shaft member rotatably driven by a drive source. A movement of the power transmission shaft member is regulated in the axial direction of the power transmission shaft member, and the power is transmitted to a winding mechanism that winds integrally with the power transmission shaft member to wind the ribbon. A worm gear, a first bevel gear that is arranged at the other end of the power transmission shaft and that transmits power to a printing mechanism that drives the carriage, and the first bevel gear that meshes with the first bevel gear. When the power transmission shaft member is moved to the worm gear side by the worm gear, the second bevel gear has a front bevel gear and a front bevel gear. If it located between the worm gear is moved to the first bevel gear side Conversely,
The printer according to claim 1, wherein the second bevel gear is positioned in a direction opposite to the worm gear of the first bevel gear. 2. The printer according to claim 1, wherein the second bevel gear is provided with a substantially cylindrical locking portion with which the end face on the small diameter side of the first bevel gear abuts. .